Field of the Invention
Embodiments of the invention relate to the field of fuses. More particularly, the present invention relates to a one-piece tuning fork terminal design and a two piece housing which provides strain relief and overstress protection during insertion.
Discussion of Related Art
As is well known, a fuse (short for “fusible link”) is an overcurrent protection device used in electrical circuits. In particular, when too much current flows, a fuse link breaks or opens thereby protecting the electrical circuit from this increased current condition. A “fast acting’ fuse creates an open circuit rapidly when an excess current condition exists. A “time delay” fuse generally refers to the condition where the fuse does not open upon an instantaneous overcurrent condition. Rather, a time lag occurs from the start of the overcurrent condition which is needed in circuits used for motors which requires a current surge when the motor starts, but otherwise runs normally.
The terminals of a fuse may have a tuning fork configuration where a first prong is spaced from a second prong to accommodate insertion of a male or female terminal as disclosed in U.S. Pat. No. 6,407,657 the contents of which are hereby incorporated by reference. Each of the first and second prongs have a normal force toward the space formed therebetween which acts against the male receiving terminal to define an electrical connection. As these terminals are positioned within a fuse box, this normal force may degrade over time which compromises the electrical connection between the terminal prongs and the male receiving terminal. In addition, the size, shape and composition of the terminals may limit the current capacity of the fuse. Moreover, the housing needs to be configured to limit the strain forces applied to the terminals and the fusible link during assembly, installation and operation. Thus, there is a need for an improved fuse employing tuning fork terminal configurations with an increased current capacity and a housing design to provide terminal insertion protection and strain relief.